Evaluate Trend Surface over a Grid

Evaluate trend surface over a grid.

Usage

trmat(obj, xl, xu, yl, yu, n)

Arguments

obj

object returned by surf.ls or surf.gls

xl

limits of the rectangle for grid

xu

ditto

yl

ditto

yu

ditto

n

use n x n grid within the rectangle

Value

list with components x, y and z suitable for contour and image.

References

Ripley, B. D. (1981) Spatial Statistics. Wiley.

Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.

See also

surf.ls, surf.gls

Examples

data(topo, package="MASS")
topo.kr <- surf.ls(2, topo)
trsurf <- trmat(topo.kr, 0, 6.5, 0, 6.5, 50)